1. Field of the Invention
The present invention relates to the technical field of nano materials and, more specifically, to a method for preparing a fluorine-doped lamellar black titanium dioxide nano material. This nano material owns the advantages of both superior optical absorption and electrochemical performance, so it can be used as a catalyst for photocatalysis application, as well as a photoanode material in dye-sensitized solar cells.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
Titanium dioxide (TiO2) is an environmentally friendly, chemically stable and low-cost semiconductor material widely used in many fields including photoelectrochemical catalysis, dye-sensitized solar cells, perovskite solar cells, and lithium-ion batteries owing to its excellent charge transport performance, high catalytic activity under light irradiation and other feature. However, common TiO2 material possesses a distinct disadvantage of wide band gap (˜3 eV), which may restricts its absorption in visible light region and carrier transport/separating ability. Therefore, modifying the electron energy level of TiO2 to narrow the bandgap, and consequently enhance the light absorption and carrier transport/separation ability of TiO2 is of great importance to its performance improvement. Herein, we have prepared a new-type fluorine-doped lamellar black TiO2 nanomaterial by adopting a low-temperature hydrothermal synthesis method, which uses tetra-n-butyl titanate as the titanium source, n-propanol as the solvent and hydrofluoric acid as the surface agent. Specifically, trivalent titanium defects are generated in the black TiO2 as a result of the fluorine doping, making the electron energy level structure improved to some extent. The black feature of the TiO2 enables the absorption of more sunlight, and the lamellar-nanosheet structure benefits in increasing the specific surface area, thereby improving the photocatalytic performance of the material.